This invention relates to feeders for feeding product on discrete volumetric-measured changes and more particularly to volumetric feeders of large particulate products. The feeder is useful for filling product into open pouches preferably comprising a train of pouches temporarily connected serially at common edge or vertical seam seals, and is particularly used for feeding larger particulate product into larger pouches, including pouches of the stand-up pouch configuration.
In the past, it has been known to feed product into pouches through the use of a feeder and a filler wheel about which a train of open-top pouches is directed. Product is fed to a filler wheel and passes through spouts inserted in the open-top mouths of the pouches. Examples of such apparatus are found, for example, in U.S. Pat. Nos. 3,821,873; 5,320,146 and 6,119,440. U.S. Pat. No. 5,320,146 describes a volumetric feeder where a belt is disposed about a feeder wheel to close off the bottoms of fixed, open bottom volumetric cavities, but is pulled away to dump the fill in the cavity through its bottom discharge port and into a spout for pouch filling. A cup feeder or dispenser 14 is used to dispense product onto a top surface of a feeder wheel, the circular discharge end of the dispenser facing the wheel depositing product on the plate as it moves thereunder.
While these known devices have certain particular utilities, they do not provide systems capable of adequately handling large particulate products in volumetric measure. Such larger particulates as cereal, candies, pet foods, chips, snacks and the like are typically larger than the product dispensed in prior devices (such as powders). The larger particulates are fragile, frequently assymetrically shaped, and generally difficult to handle with accurate measure and without degrading the product by abrasion and the like. For example, if large particulates were deposited by the dispensing spout of U.S. Pat. No. 5,320,146, they could be captured by the lower edge of the spout on the ring feeder and by each other, or by the rotating plate beneath the cup feeder, for example, grinding or damaging partially released product. In addition, large particulates can bridge in such a dispenser, or in the cylindrical volumetric receiving chambers and frequently cause uneven or inaccurate fills. And it will be appreciated that in volumetric feeding and pouch filling, consistent density of the product charge is highly desired for consistent volume and product packaging.
Moreover, there is no provision in the known prior systems (other than a parts change-out) for adjusting the volumetric product charge for change size changes or based on long term trends demanding adjustment in product density changes during operation. And there is nothing suggested to avoid the anticipated bridging problems of large particulates in the system.
Accordingly, it is one objective of this invention to provide improved apparatus and methods for feeding product in large particulate form, as opposed to smaller particulates such as powder, and in accurate volumetric charges for downstream handling such as for filling into pouches.
Another objective of the invention has been to provide improved apparatus and methods for adjusting volumetric chambers in a volumetric feeder to desired volumetric product charges.
A further objective of the invention has been to provide apparatus for handling large particulate products in a feeder without producing bridging.
To these and other ends, the invention in a preferred embodiment includes a volumetric feeder comprising a wheel defining a plurality of volumetric product receiving and discharging chambers fed by a product rate feeder. Product is rate-fed onto a plate and into a plurality of adjustable volumetric chambers. An entire side of the chamber comprising a major chamber wall is defined by a belt engaging a periphery of the wheel. The belt is directed away from the wheel to open the chamber side and to allow product to discharge from the chamber into a large spout mouth for depositing into an open pouch, for example.
Product is fed onto the wheel via rate-driven belt and vibratory tray, with no cup or tube feed and no product grinding. A sensor senses the height of the large particulate product on the wheel and speeds or slows the product rate feeder as the height or depth of product on the wheel decreases or increases respectively.
Since a major chamber wall is defined by the discharge belt which simply moves away from the chamber or discharge, the discharge opening is larger in cross-section than the cross-section of product flow in the chamber and product is easily discharged with no bridging. Moreover, the gentle belt departure from the chamber allows a very gentle discharge motion for fragile particulates.
The volumetric chambers of the wheel are preferably defined by extruded members with an open chamber side and a movable puck which can be raised or lowered to decrease or increase the chamber volume, respectively. These pucks can be adjusted to set position for a specific volumetric charge desired. The invention contemplates also their on-the-fly adjustment to adapt the feeder to long term trends in the product density or in the volumetric product charges being produced.
Thus, the invention provides improved apparatus and methods for feeding consistent volumetric charges of large particulate product without undue product degradation or bridging. Large particulate products can be packaged in pouches running in typical fashion but without the drawbacks of prior pouch systems with respect to handling large particulates.
These and other objectives and advantages will become readily apparent from the following detailed description of a preferred embodiment of the invention and from the drawings in which: